Table 3.

Maximum-likelihood estimates and 95% confidence intervals based on the non-homogeneous and the homogeneous multi-state model

Description	Parameter	MLE (95% CI)
		Non-homogeneous model			Homogeneous model
		40–49 years	50–59 years	60–69 yearsa
Transition rate from free of BC to progressive PCDP	λ12(t)	–	0.00276 (0.00269, 0.00283)	0.00381 (0.00371, 0.00390)	0.00306 (0.00301, 0.00311)
Transition rate from progressive PCDP to CP	λ23(t)	0.385 (0.342, 0.428)	0.464 (0.436, 0.492)	0.284 (0.267, 0.301)	0.418 (0.400, 0.436)
Ratio of λ14(t) to λ12(t)	r	0.00182 (0, 0.00523)			9.999×10−4 (0, 3.432×10−3)
Sensitivity	S	0.880 (0.852, 0.909)			0.924 (0.901, 0.947)
-2*log(likelihood)	NA	198,024			198,878
Mean sojourn time (year)	$\frac{1}{{\lambda }_{23}\left(t\right)}$	2.60 (2.31, 2.89)	2.16 (2.03, 2.29)	3.52 (3.31, 3.73)	2.39 (2.29, 2.49)

Abbreviations: BC breast cancer, CI confidence interval, CP clinical phase, MLE maximum likelihood estimate, MST mean sojourn time, NA not applicable, PCDP preclinical screen-detectable phase

Likelihood ratio test of the non-homogeneous versus the homogeneous model: ${\chi }_{\left(3\right)}^2$ = 854, P <0.001

^a9.65% of the women were invited to screening at age 70–74